lidocaine hydrochloride + phenazone: clinical use

Prescribing considerations

• Confirm an intact tympanic membrane before prescribing.
• Stop treatment and reassess if otorrhoea develops or symptoms worsen or fail to improve.
• Use caution in infants under 3 months and people susceptible to methaemoglobinaemia, including those with haemoglobinopathies or G6PD deficiency.
• The product may produce a positive anti-doping test.

Contraindications and cautions

• Hypersensitivity to lidocaine, phenazone or any excipient.
• Infectious or traumatic tympanic-membrane perforation, including myringotomy or a ventilation tube.

Monitoring

• Clinical response and any rapid or significant deterioration.
• New ear discharge, hearing change, vertigo or other signs suggesting perforation.
• Local itching, rash or auditory-canal hyperaemia.
• Features of methaemoglobinaemia in susceptible patients.

Clinical pharmacology

Phenazone is a pyrazolone analgesic with anti-inflammatory properties; lidocaine is an amide local anaesthetic. Systemic absorption is unlikely through an intact tympanic membrane.

Formulation and product differences

• The selected product is a clear, colourless to yellow-brown solution containing sodium thiosulfate, ethanol, glycerol and purified water.
• It is supplied in a light-protective brown-glass bottle with a separate dropper applicator.
• After first opening, the bottle has a six-month in-use shelf life.

Ear drops

Route: Otic

Strengths: 40 mg + 10 mg/g